// when start_routine (and hence virtual idle_loop) is called and when joining.
template<typename T> T* new_thread() {
- T* th = new T();
- th->nativeThread = std::thread(&ThreadBase::idle_loop, th); // Will go to sleep
- return th;
+ std::thread* th = new T;
+ *th = std::thread(&T::idle_loop, (T*)th); // Will go to sleep
+ return (T*)th;
}
void delete_thread(ThreadBase* th) {
th->mutex.unlock();
th->notify_one();
- th->nativeThread.join(); // Wait for thread termination
+ th->join(); // Wait for thread termination
delete th;
}
void ThreadBase::notify_one() {
- std::unique_lock<Mutex>(this->mutex);
+ std::unique_lock<Mutex> lk(mutex);
sleepCondition.notify_one();
}
// Pick and init the next available split point
SplitPoint& sp = splitPoints[splitPointsSize];
+ sp.spinlock.acquire(); // No contention here until we don't increment splitPointsSize
+
sp.master = this;
sp.parentSplitPoint = activeSplitPoint;
sp.slavesMask = 0, sp.slavesMask.set(idx);
sp.nodes = 0;
sp.cutoff = false;
sp.ss = ss;
-
- // Try to allocate available threads and ask them to start searching setting
- // 'searching' flag. This must be done under lock protection to avoid concurrent
- // allocation of the same slave by another master.
- Threads.mutex.lock();
- sp.mutex.lock();
-
sp.allSlavesSearching = true; // Must be set under lock protection
+
++splitPointsSize;
activeSplitPoint = &sp;
activePosition = nullptr;
+ // Try to allocate available threads
Thread* slave;
while ( sp.slavesMask.count() < MAX_SLAVES_PER_SPLITPOINT
- && (slave = Threads.available_slave(activeSplitPoint)) != nullptr)
+ && (slave = Threads.available_slave(&sp)) != nullptr)
{
- sp.slavesMask.set(slave->idx);
- slave->activeSplitPoint = activeSplitPoint;
- slave->searching = true; // Slave leaves idle_loop()
- slave->notify_one(); // Could be sleeping
+ slave->spinlock.acquire();
+
+ if (slave->can_join(activeSplitPoint))
+ {
+ activeSplitPoint->slavesMask.set(slave->idx);
+ slave->activeSplitPoint = activeSplitPoint;
+ slave->searching = true;
+ }
+
+ slave->spinlock.release();
}
// Everything is set up. The master thread enters the idle loop, from which
// it will instantly launch a search, because its 'searching' flag is set.
// The thread will return from the idle loop when all slaves have finished
// their work at this split point.
- sp.mutex.unlock();
- Threads.mutex.unlock();
+ sp.spinlock.release();
Thread::idle_loop(); // Force a call to base class idle_loop()
assert(!searching);
assert(!activePosition);
+ searching = true;
+
// We have returned from the idle loop, which means that all threads are
- // finished. Note that setting 'searching' and decreasing splitPointsSize must
- // be done under lock protection to avoid a race with Thread::available_to().
- Threads.mutex.lock();
- sp.mutex.lock();
+ // finished. Note that decreasing splitPointsSize must be done under lock
+ // protection to avoid a race with Thread::can_join().
+ sp.spinlock.acquire();
- searching = true;
--splitPointsSize;
activeSplitPoint = sp.parentSplitPoint;
activePosition = &pos;
*bestMove = sp.bestMove;
*bestValue = sp.bestValue;
- sp.mutex.unlock();
- Threads.mutex.unlock();
+ sp.spinlock.release();
}
while (!thinking && !exit)
{
- Threads.sleepCondition.notify_one(); // Wake up the UI thread if needed
+ sleepCondition.notify_one(); // Wake up the UI thread if needed
sleepCondition.wait(lk);
}
}
+// MainThread::join() waits for main thread to finish the search
+
+void MainThread::join() {
+
+ std::unique_lock<Mutex> lk(mutex);
+ sleepCondition.wait(lk, [&]{ return !thinking; });
+}
+
+
// ThreadPool::init() is called at startup to create and launch requested threads,
// that will go immediately to sleep. We cannot use a c'tor because Threads is a
// static object and we need a fully initialized engine at this point due to
void ThreadPool::exit() {
delete_thread(timer); // As first because check_time() accesses threads data
+ timer = nullptr;
for (Thread* th : *this)
delete_thread(th);
+
+ clear(); // Get rid of stale pointers
}
// If zero (default) then set best minimum split depth automatically
if (!minimumSplitDepth)
- minimumSplitDepth = requested < 8 ? 4 * ONE_PLY : 7 * ONE_PLY;
+ minimumSplitDepth = 5 * ONE_PLY ;
while (size() < requested)
push_back(new_thread<Thread>());
}
-// ThreadPool::wait_for_think_finished() waits for main thread to finish the search
-
-void ThreadPool::wait_for_think_finished() {
-
- std::unique_lock<Mutex> lk(main()->mutex);
- sleepCondition.wait(lk, [&]{ return !main()->thinking; });
-}
-
-
// ThreadPool::start_thinking() wakes up the main thread sleeping in
// MainThread::idle_loop() and starts a new search, then returns immediately.
void ThreadPool::start_thinking(const Position& pos, const LimitsType& limits,
StateStackPtr& states) {
- wait_for_think_finished();
-
- SearchTime = now(); // As early as possible
+ main()->join();
Signals.stopOnPonderhit = Signals.firstRootMove = false;
Signals.stop = Signals.failedLowAtRoot = false;
RootMoves.push_back(RootMove(m));
main()->thinking = true;
- main()->notify_one(); // Starts main thread
+ main()->notify_one(); // Wake up main thread: 'thinking' must be already set
}
projects / stockfish / blobdiff